I've been bearded since... 16, I think. I've tried to be clean-shaven a couple of times, but my hair just grows too fast for it to be practical, so I just keep it trimmed to a neatish shape.
Viz the girls'-opinion-of-facial-hair thing, it obviously varies. If it's hiding a double-chin, obviously it's not terribly impressive. I've never had a straight-out refusal on account of my facial hair, but various girlfriends have displayed different levels of keen-ness.
Viz the itching thing that everyone complains about, that takes a small amount of time to go away, and you can alleviate most of it just by washing your beard when you wash your hair.